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authorScott Mayhew <smayhew@redhat.com>2016-06-07 22:14:48 +0300
committerTrond Myklebust <trond.myklebust@primarydata.com>2016-07-19 23:23:24 +0300
commitce52914eb76efd62aa48d738cf845b37852bf920 (patch)
treec6a0ab9112d231ab15039bd310b5ff332a0e1572 /fs/nfs
parente68fd7c8071d541d3f2f7eed5814b63e865dd277 (diff)
downloadlinux-ce52914eb76efd62aa48d738cf845b37852bf920.tar.xz
sunrpc: move NO_CRKEY_TIMEOUT to the auth->au_flags
A generic_cred can be used to look up a unx_cred or a gss_cred, so it's not really safe to use the the generic_cred->acred->ac_flags to store the NO_CRKEY_TIMEOUT flag. A lookup for a unx_cred triggered while the KEY_EXPIRE_SOON flag is already set will cause both NO_CRKEY_TIMEOUT and KEY_EXPIRE_SOON to be set in the ac_flags, leaving the user associated with the auth_cred to be in a state where they're perpetually doing 4K NFS_FILE_SYNC writes. This can be reproduced as follows: 1. Mount two NFS filesystems, one with sec=krb5 and one with sec=sys. They do not need to be the same export, nor do they even need to be from the same NFS server. Also, v3 is fine. $ sudo mount -o v3,sec=krb5 server1:/export /mnt/krb5 $ sudo mount -o v3,sec=sys server2:/export /mnt/sys 2. As the normal user, before accessing the kerberized mount, kinit with a short lifetime (but not so short that renewing the ticket would leave you within the 4-minute window again by the time the original ticket expires), e.g. $ kinit -l 10m -r 60m 3. Do some I/O to the kerberized mount and verify that the writes are wsize, UNSTABLE: $ dd if=/dev/zero of=/mnt/krb5/file bs=1M count=1 4. Wait until you're within 4 minutes of key expiry, then do some more I/O to the kerberized mount to ensure that RPC_CRED_KEY_EXPIRE_SOON gets set. Verify that the writes are 4K, FILE_SYNC: $ dd if=/dev/zero of=/mnt/krb5/file bs=1M count=1 5. Now do some I/O to the sec=sys mount. This will cause RPC_CRED_NO_CRKEY_TIMEOUT to be set: $ dd if=/dev/zero of=/mnt/sys/file bs=1M count=1 6. Writes for that user will now be permanently 4K, FILE_SYNC for that user, regardless of which mount is being written to, until you reboot the client. Renewing the kerberos ticket (assuming it hasn't already expired) will have no effect. Grabbing a new kerberos ticket at this point will have no effect either. Move the flag to the auth->au_flags field (which is currently unused) and rename it slightly to reflect that it's no longer associated with the auth_cred->ac_flags. Add the rpc_auth to the arg list of rpcauth_cred_key_to_expire and check the au_flags there too. Finally, add the inode to the arg list of nfs_ctx_key_to_expire so we can determine the rpc_auth to pass to rpcauth_cred_key_to_expire. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/file.c4
-rw-r--r--fs/nfs/internal.h2
-rw-r--r--fs/nfs/write.c6
3 files changed, 7 insertions, 5 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 717a8d6af52d..6bcd8913e8a9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -432,7 +432,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
return status;
NFS_I(mapping->host)->write_io += copied;
- if (nfs_ctx_key_to_expire(ctx)) {
+ if (nfs_ctx_key_to_expire(ctx, mapping->host)) {
status = nfs_wb_all(mapping->host);
if (status < 0)
return status;
@@ -645,7 +645,7 @@ static int nfs_need_check_write(struct file *filp, struct inode *inode)
ctx = nfs_file_open_context(filp);
if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) ||
- nfs_ctx_key_to_expire(ctx))
+ nfs_ctx_key_to_expire(ctx, inode))
return 1;
return 0;
}
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index fa88609f85e3..d2260e67334f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -497,7 +497,7 @@ void nfs_init_cinfo(struct nfs_commit_info *cinfo,
struct inode *inode,
struct nfs_direct_req *dreq);
int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
-bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode);
void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio);
#ifdef CONFIG_MIGRATION
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index e1c74d3db64d..0b949a06b297 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1195,9 +1195,11 @@ nfs_key_timeout_notify(struct file *filp, struct inode *inode)
/*
* Test if the open context credential key is marked to expire soon.
*/
-bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
{
- return rpcauth_cred_key_to_expire(ctx->cred);
+ struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
+
+ return rpcauth_cred_key_to_expire(auth, ctx->cred);
}
/*